Ms. Carroll, a free-lance reporter for The Christian Science Monitor, was abducted on 7 January in Baghdad, as she traveled to the office of an Iraqi politician for an interview. Ms. Carroll's Iraqi translator was killed in the abduction, which was attributed to a group called the "Revenge Brigades." Later, a senior Iraqi official indicated that Carroll was being held by the Islamic Army in Iraq, another terrorist group. At one point, Carroll's kidnappers threatened to kill her unless all female prisoners in Iraq were released. That deadline expired, with no word about her fate.

Details of Ms. Carroll's release are still sketchy. She has reportedly said that her kidnappers suddenly "came to me and said we're going." She was loaded into an automobile, driven to the offices of an Iraqi Political Party, and released. She contacted American officials by phone from the party's headquarters.

As a general rule, kidnappers release their captives only because (a) a ransom has been paid; (b) the captive's "usefulness" to the criminals--or in this case, a terrorist organization--has been exhasted, or (c) security forces are closing in, and the bad guys elect to cut and run. At this point, I'm leaning toward option three. Less than two weeks ago, terrorists released three Christian peace activists because they believed that U.S. and Iraqi forces were closing in. It's much easier for kidnappers to cover their tracks if they don't have a hostage in tow--or leave a corpse behind.

Additionally, there is no evidence (yet) that the U.S. government or the Monitor paid a ransom to Carroll's kidnappers, so that doesn't appear to be the reason for her release. And certainly, Ms. Caroll's potential value to the terrorists was far from exhausted. As the only female American hostage in Iraq, Ms. Carroll was a high-profile captive; the kidnapping generated tons of media coverage for both the victim and her captors. Why give up such a high-value asset unless you're worried that the Americans or Iraqi security forces are about to kick in the front door?

We'll learn more about Ms. Carroll's ordeal, her kidnappers, and the circumstances surrounding her release in the coming weeks. In the meantime, we should all be greatful that she's leaving Iraq alive and well.